1. Field of the Invention
The present invention relates to a silver halide photographic light-sensitive material, and more particularly to a silver halide photographic light-sensitive material which excels in sensitivity, gradation, and reciprocity.
2. Description of the Related Art
In order to provide a silver halide photographic light-sensitive material which has sufficient property regarding to gradation and reciprocity, it has been generally practiced to use silver halide grains containing metal other than silver or ions of the metal. As is known in the art, however, the use of such silver halide grains reduces the sensitivity of the material.
Known as applicable sensitization are chalcogen sensitization, gold sensitization, and reduction sensitization. They can be used either singly or in combination. Known examples of chalcogens are sulfur, selenium, and tellurium. Sensitization using sulfur is the most commonly practiced sensitization, widely employed in preparing practical emulsions. Sensitization using selenium is less popular than sulfur sensitization, but various methods of performing selenium sensitization are disclosed a number of patent specifications. Tellurium is not put to practical use in sensitization, and tellurium sensitization is scarcely introduced in research literature. Tellurium sensitizers and the conditions for using them are specified in only a few references, such as British Patents 1,295,462 and 1,396,696, and Canadian Patent 800,958.